Box Model

CSS inset Property

Shorthand for top, right, bottom, and left properties

Syntax

CSS
inset: auto | <length> | <percentage>;

Values

ValueDescription
autoAutomatic positioning
0Stretches to fill positioned parent
<length>Fixed offset (1-4 values)

Example

CSS
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

Understanding CSS inset

The CSS inset property shorthand for top, right, bottom, and left properties. As part of the Box Model module in CSS, it is one of the most commonly used properties for controlling the visual presentation of web pages.

You can set inset to values such as auto, 0, <length>, among others. Each value changes how the browser renders the affected element, giving you fine-grained control over your page layout and design. Choosing the right value depends on the specific design requirements of your project.

Common use cases for the inset property include responsive web design, component-based layouts, and creating visually consistent interfaces across devices. It works closely with related properties like top, right, bottom to achieve complex styling effects. Understanding how these properties interact helps you write cleaner, more maintainable stylesheets.

Browser support for inset is excellent across all modern browsers including Chrome, Firefox, Safari, and Edge. For older browsers, consider using fallback values or progressive enhancement strategies. The property can also be set dynamically via JavaScript using element.style.inset or the CSS custom properties (variables) approach for theming.

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